The Secret of Immortality in the End of the World

There is a mysterious spell in this world called the Art of Changing Love. Chang Sheng possesses the art of immortality, and she is an immortal person. However, she can live forever, but she cannot let the person she loves also live together. He has been reincarnated in the mortal world. She has forgotten the mortal world. She is an ancient person who lived more than a thousand years ago, and he is a serious and majestic special police officer. What kind of sparks will arise between these two people from different worlds? A strange and mysterious unsolved case, the hand of cause and effect has never let go of anyone. When one day, she recalls the past, will they still be the same as when they first met?